Your Traveler III is a 1979 model assembled on January 18, 1979 (0189 is the 18th day of a year ending in 9).

From Schwinn Bulletin 23, "Schwinn Bicycle Identification Numbers":

Bicycles from Japan have a production month letter in either the first or second position and a production year number in the other (first or second) position. Examples J677123 = September, 1976, 6J77123 = September, 1976.

I agree with zazenzach; the original drop bars have been replaced by tourist bars for a more upright riding position and the saddle for one probably more comfortable for the owner. You got a good deal for $20!